Chapter 13, Problem 27P

A piston-cylinder device initially contains 0.4 kg of nitrogen gas at 160 kPa and 140°C. Nitrogen is now expanded isothermally to a pressure of 80 kPa. Determine the boundary work done during this process. The properties of nitrogen are R= 0.2968 kJ/kg-K and k= 1.4. N₂ 160 kPa 140°C The boundary work done during this process is KJ.

! Required information An abrasive cutoff wheel has a diameter of 5 in, is 1/16 in thick, and has a 3/4-in bore. The wheel weighs 4.80 oz and runs at 11,700 rev/min. The wheel material is isotropic, with a Poisson's ratio of 0.20, and has an ultimate strength of 12 kpsi. Choose the correct equation from the following options: Multiple Choice о σmax= (314) (4r2 — r²) - о σmax = p² (3+) (4r² + r²) 16 σmax = (314) (4r² + r²) σmax = (314) (4² - r²)

I don't know how to solve this